Jan. 4, 2010 -- Cigarette smoking is linked to an increased risk of
diabetes, but quitting the habit, ironically, may increase diabetes risk in the
short term, a new study says.

Researchers say people who quit smoking typically gain weight, which may
explain the temporary period of increased risk for developing type 2 diabetes,
which is closely linked to obesity.

The findings are reported in the Jan. 5 issue of Annals of Internal
Medicine.

The authors stress that their findings should not deter people from quitting
smoking, which is also a risk factor for heart disease, stroke,
atherosclerosis, and cancer. They say that the health benefits of smoking
cessation outweigh the short-term risk.

"The message is: Don't even start to smoke," Hsin-Chieh Yeh, PhD, an
epidemiologist at the Johns Hopkins University School of Medicine and lead
author of the study, says in a news release. "If you smoke, give it up. That's
the right thing to do."

She says smokers who quit "have to also watch their weight" because obesity
is tied to diabetes, cardiovascular disease, and other health problems.

Researchers in 1987-1989 enrolled 10,892 middle-aged adults who did not have
diabetes and followed them for nine years. The study found that overall,
people who smoked had a 42% higher risk of developing diabetes during the
follow-up period than nonsmokers. However, smokers who quit had a 70% higher
risk of developing type 2 diabetes in the first six years after quitting than
people who had never smoked.

The risks of developing type 2 diabetes were highest in the first three
years after quitting smoking, then returned to normal after 10 years, the
researchers say.

Among those who continued smoking over that period, the chance of developing
diabetes was 30% higher than in people who had never smoked.

The study found that people who smoked the most and those who gained the
most weight after quitting had the highest likelihood for developing
diabetes.

The authors report that new quitters had significant increases in weight,
waistline measurement, and fasting blood sugar levels compared with people who
had never smoked.

Yeh and colleagues say doctors should remind patients of the benefits of
exercise, staying trim, and avoiding smoking.

"For smokers at risk for diabetes, smoking cessation should be coupled with
strategies for diabetes prevention and early detection," the authors write.

They say the study "suggests that heavy smokers with evidence of
systemic inflammation who gain substantial weight after quitting are at the
highest risk for diabetes."

"[P]hysicians should be aware of this elevated risk and should consider
countermeasures, especially for heavy smokers," the researchers say.